Stockholders’ Equity (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended						1 Months Ended			12 Months Ended								12 Months Ended
	Aug. 31, 2012	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2012	Jan. 31, 2014	Jan. 31, 2013	Oct. 31, 2011	Mar. 31, 2014 Accelerated Share Repurchase Program [Member]	Feb. 28, 2014 Accelerated Share Repurchase Program [Member]	Jan. 31, 2014 Incremental authorization to share repurchase program [Member]	Aug. 31, 2014 Treasury Stock [Member]	Aug. 31, 2013 Treasury Stock [Member]	Aug. 31, 2012 Treasury Stock [Member]	Aug. 31, 2014 Restricted Stock Units [Member]	Aug. 31, 2013 Restricted Stock Units [Member]	Aug. 31, 2012 Restricted Stock Units [Member]	Aug. 31, 2014 2006 Plan [Member]	Jan. 16, 2014 2006 Plan [Member]	Aug. 31, 2014 Employee Stock Option [Member]	Aug. 31, 2013 Board of Director Stock Option [Member]	Aug. 31, 2014 Minimum [Member] 2006 Plan [Member]	Aug. 31, 2014 Maximum [Member] 2006 Plan [Member]	Aug. 31, 2014 Employee Stock [Member]	Aug. 31, 2014 Employee Stock [Member] Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation percentage																								10.00%
Stock’s fair market value																								$ 25,000
Discount price percentage																							15.00%
Additional shares authorized																		6,600,000
Shares available for grant																	7,800,000						800,000
Stock-based compensation cost recognized		3,742,000	3,630,000	4,295,000
Excess tax benefits		1,700,000	1,200,000	1,200,000
Unvested unrecognized compensation cost		4,900,000
Unvested unrecognized compensation cost, period		1 year 10 months 24 days
Contractual term																					7 years	10 years
Vesting period														3 years					3 years	1 year
Weighted average fair value of stock options granted		$ 6.82	$ 4.69	$ 2.88
Proceeds from exercise of stock options		17,407,000	16,343,000	280,000
Total intrinsic value of options exercised		13,000,000	3,800,000	100,000
Aggregate fair value of vested restricted stock														1,100,000	900,000	500,000
Shares repurchase authorized amount	40,000,000	105,000,000	40,000,000	40,000,000	80,000,000	55,000,000	30,000,000		40,000,000	40,000,000
Shares acquired through stock repurchase program	100,000							0	2,100,000		4,080,000	3,332,000	4,157,000
Total cost for shares acquired through stock repurchase program	1,100,000	80,045,000	35,480,000	31,102,000					40,000,000		80,045,000	35,480,000	31,102,000
Final price paid per share								$ 19.13
Weighted-average price per share		$ 19.61
Dividends Payable, Amount Per Share		$ 0.09
Dividends Payable		$ 4,852,000
Dividends Payable, Date of Record		Nov. 12, 2014
Dividends Payable, Date to be Paid		Nov. 21, 2014